Magnetic resonance imaging (MRI) is widely used for medical diagnosis. During an MRI scan, there may be one or more excitations in each of which one or more slices of an object may be excited. In an excitation, an excitation RF pulse may be applied to excite one or more slices of the object in conjunction with a slice selective gradient. Generally, a waveform generator of an MRI scanner may generate an RF pulse. The RF pulse generated by the waveform generator may be amplified using a radiofrequency power amplifier (RFPA). The RFPA may amplify the RF pulse (e.g., the power of the RF pulse, the voltage of the RF pulse) such that the amplified RF pulse may drive the RF coils to generate a magnetic field of a sufficient magnitude. However, the waveform of the amplified RF pulse generated by the RFPA may be different from designed, which is referred to as distortion. When the amplified RF pulse with distortion is applied on the RF coils to generate a magnetic field, the magnetic field together with a slice selective gradient may excite one or more undesired slices, which may cause artifacts in an image generated based on the MRI scan. Therefore, it is desirable to provide systems and methods to reduce or eliminate the effect of the distortion.